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Piezoelectric energy harvesting is the process of extracting electrical energy using energy harvester devices. Any stress in the piezoelectric material will generate induced voltage. Previous energy harvester device with stiff cantilever beam was generated low harvested energy. A flexural piezoelectric energy harvester is proposed to improve the generated harvesting energy. Polyvinylidene difluoride is a polymer piezoelectric material attached to a flexible circuit made of polyimide. Four interdigitated electrode circuits were designed and outsourced for fabrication. The polyvinylidene difluoride was then attached to the interdigitated electrode circuit, and a single clear adhesive tape was used to bind them. Four piezoelectric energy harvesters and ultrasonic ceramic generators were experimentally tested using a sieve shaker. The sieve shaker contains a two-speed oscillator, with M1=0.025 m/s and M2=0.05 m/s. It was used to oscillate the energy harvester devices. The resulting induced voltages were then measured. Design 4, with the widest width of electrode fingers and the widest gap between electrode fingers, had the highest power generated at an output load of 0.745 µW with the M2 oscillation speed. The oscillation speed of the sieve shaker impacted the energy harvester devices as a higher oscillation speed gave higher generated power.

The use of red, green, and blue ( RGB ) light-emitting-diode ( LED ) is a new trend in monochromatic colorimetric sensing due to cost-effective implementation. However, the application of RGB LED in pH measurement depends on the performance of the LED colour towards the colorimetric solution of interest, hence, needs to be evaluated. This work evaluated the performance of RGB LED for pH measurement system based on colorimetric approach using phenol red as a reagent. The main objective was to identify the LED colour with the best performance in terms of signal response and a bsorbance behavior. In this work, LED and photodiode were used as optical components and NI USB DAQ with LabView as the processing software. Four samples with known pH values were prepared and tested to obtain the voltage and absorbance behavior of each LED colour. Among all, the blue LED with wavelength ranged between 450 - 495 nm showed the best sensing behavior based on its linearity and error. Both voltage response and absorbance produced linear correlation with R 2=0.883 and R 2=0.9803, respectively. The significant finding from this study is useful in selecting the best RGB LED that is suitable for colorimetric pH measurement with phenol red as its colorimetric reagent.

Gas Metal Arc Welding (GMAW) are well known due to its cost effective and easy accessibility. The technique is commonly used in shipping maintenance to repair corrosion and erosion affected propeller blades. Recently, studies of the Friction Stir Process (FSP) have shown its capability to generate a very fine microstructure and enhancement of the metal surface properties. This paper proposes an integrated approach for repairing larger sized nickel-aluminum bronze (NAB) components using a single robotic system. The process includes surface cleaning, weld deposition (WD), welding deposition Friction Stir Process (WD-FSP), surface and contour finishing. The mechanical properties, including hardness, cavitation erosion and corrosion performance, are tested on as-cast NAB, WD and WD-FSP surfaces. The weld deposition and WD-FSP surfaces showed an enhancement in hardness compared to as-cast NAB. As for cavitations erosion and corrosion, the weld deposition and WD-FSP sample exhibited an improvement in the cumulative mass loss and shifting of the electrode potential to the more noble section signifying that using the proposed approach is feasible for NAB repair.

In acoustic receiver design, the receiving sensitivity and bandwidth are two primary parameters that determine the performance of a device. The trade-off between sensitivity and bandwidth makes the design very challenging, meaning it needs to be fine-tuned to suit specific applications. The ability to design a PMUT with high receiving sensitivity and a wide bandwidth is crucial to allow a wide spectrum of transmitted frequencies to be efficiently received. This paper presents a novel structure involving a double flexural membrane with a fluidic backing layer based on an in-plane polarization mode to optimize both the receiving sensitivity and frequency bandwidth for medium-range underwater acoustic applications. In this structure, the membrane material and electrode configuration are optimized to produce good receiving sensitivity. Simultaneously, a fluidic backing layer is introduced into the double flexural membrane to increase the bandwidth. Several piezoelectric membrane materials and various electrode dimensions were simulated using finite element analysis (FEA) techniques to study the receiving performance of the proposed structure. The final structure was then fabricated based on the findings from the simulation work. The pulse–echo experimental method was used to characterize and verify the performance of the proposed device. The proposed structure was found to have an improved bandwidth of 56.6% with a receiving sensitivity of −1.8864 dB rel 1 V µPa. For the proposed device, the resonance frequency and center frequency were 600 and 662.5 kHz, respectively, indicating its suitability for the targeted frequency range.

Research in prognosis maintenance, a branch of condition-based maintenance has received more attention from researchers lately. They focus on predicting when is the most suitable time to perform maintenance. Our review suggests that investigation on feature extraction in development of prognosis prediction model is still limited. This paper presents our study to find the most effective method for features extraction from maintenance monitoring data. The chosen features set should effectively improve the prognosis maintenance model performance. There have been several investigations to study feature extraction methods; however, the appropriate one is yet to be identified. In this research, we used datasets publicly available from National Aeronautics and Space Administration (NASA) army research laboratory. These datasets were generated through a simulation of the turbofan engine by using Commercial Modular Aero-Propulsion System Simulation (CMAPSS) software developed by NASA army research laboratory. Features extraction methods such as correlation among sensors, correlation among the outputs, variable weighing and treated data methods were studied in this research. Next, the extracted features were applied to the regression tree for searching an appropriate prognosis model. Based on the Remaining Useful Life (RUL) prediction results, the correlation among sensors method was found as the best method that can represent the most useful features for the prediction model.

Introduction Electronic cigarettes (e-cigarettes) are new smoking devices that have gained popularity recently. However, there is limited evidence on e-cigarette consumption in Malaysia. This study aims to determine the prevalence, risk factors and perception associated with e-cigarette use among those attending government hospitals and health clinics in Malaysia. Methods A cross-sectional hospital-based study was conducted in seven public hospitals and health clinics in Malaysia, which were selected through a twostage cluster sampling. A validated questionnaire was used to obtain data from the selected participants. Multivariable logistic regression was employed to determine the association between sociodemographics and perceptions of e-cigarette use. Results Almost three-quarters (73.6%; n=923/1254) of participants were aware of e-cigarettes and 13.2% (n=122/923) reported having ever used e-cigarettes. The prevalence was significantly higher among males (18.1%), smokers (21.4%), and younger age group 18–34 years (30.2%). Ever users showed favourable perceptions towards e-cigarettes compared to non-users (23.3% vs 30.14%, p

Brunei Darussalam is rich in natural resources, including fossil fuels and biodiversity, which it uses to develop its economy, while at the same time, conserve them in order to ensure that it maintains a clean and green environment. However, as a developing Islamic nation, Brunei Darussalam cannot escape from creating an undesirable change to its environment. Pollution is considered to be one of the most critical problems facing the environment today. Haze and solid waste are among the most prominent kinds of pollution in the country. The paper will look into the attitudes of the largely-Muslim society in Brunei Darussalam on environmental pollution, and their knowledge and behaviour regarding this issue. Finally, the paper attempts to explain what seems to be uncaring attitude and behaviour among Muslims in Brunei Darussalam towards environmental issues.

Robotic friction stir processing (FSP) has not been widely researched to date. This is perhaps due to the limited force capabilities of industrial robots in comparison with dedicated commercial FSP equipment. When operating a FSP machine, the force used to plunge the tools may range from 5000 to 8000 N which is currently beyond the capability of most robots. However, the capacity of robotic manipulators is increasing, so low force friction stir processing is becoming feasible. The ability of the robot arm to apply a controlled force that is normal to a 3-dimensional surface without the need to reorient the workpiece makes it a very useful tool for FSP of complex components. In this analysis, a robot arm with a capacity of 2500 N is used to improve the surface properties of nickel aluminum bronze (NAB) using low force FSP. Multiple passes were applied to the surface of the test sample for a more consistent spread of the stir zone. The sample was then microhardness tested and demonstrated a 62 pct increase in surface hardness. Cavitation erosion testing of the original and processed surfaces was also performed as per ASTM G-32. The erosion rate of the processed NAB sample was 44 pct of the rate experienced by the original cast NAB sample. Finally, the corrosion potentials of FSP NAB were measured at 45 mV less anodic than the unprocessed material, indicating that the processed material is more noble relative to the cast NAB sample.

Brunei Darussalam is a peaceful and prosperous nation in Southeast Asia, sheltered from heavy industrialisation and excessive exploitation of its natural resources. Decades of dependence on oil and natural gas have brought wealth, but at the same time placed the small nation in a dilemma over the failure of its economy to diversify. Tourism has been distinguished as one of the key areas which can remedy the country's economic condition. Adamant in embracing sustainable development – development that promotes the quality of life of people, economic prosperity and environmental protection – the country is keen to ensure that it adopts a sustainable approach to developing its tourism industry. This paper attempts to identify the prospect as well as challenges of sustainable tourism in Brunei Darussalam from the perspective of the business organisations or enterprises in the tourism industry, based on data that were collected from a survey conducted among travel, transport, hospitality and visitor attraction sectors in the country.

Background: Myocardial injury after noncardiac surgery (MINS) was defined as prognostically relevant myocardial injury due to ischemia that occurs during or within 30 days after noncardiac surgery. The study’s four objectives were to determine the diagnostic criteria, characteristics, predictors, and 30-day outcomes of MINS. Methods: In this international, prospective cohort study of 15,065 patients aged 45 yr or older who underwent in-patient noncardiac surgery, troponin T was measured during the first 3 postoperative days. Patients with a troponin T level of 0.04 ng/ml or greater (elevated “abnormal” laboratory threshold) were assessed for ischemic features (i.e., ischemic symptoms and electrocardiography findings). Patients adjudicated as having a nonischemic troponin elevation (e.g., sepsis) were excluded. To establish diagnostic criteria for MINS, the authors used Cox regression analyses in which the dependent variable was 30-day mortality (260 deaths) and independent variables included preoperative variables, perioperative complications, and potential MINS diagnostic criteria. Results: An elevated troponin after noncardiac surgery, irrespective of the presence of an ischemic feature, independently predicted 30-day mortality. Therefore, the authors’ diagnostic criterion for MINS was a peak troponin T level of 0.03 ng/ml or greater judged due to myocardial ischemia. MINS was an independent predictor of 30-day mortality (adjusted hazard ratio, 3.87; 95% CI, 2.96–5.08) and had the highest population-attributable risk (34.0%, 95% CI, 26.6–41.5) of the perioperative complications. Twelve hundred patients (8.0%) suffered MINS, and 58.2% of these patients would not have fulfilled the universal definition of myocardial infarction. Only 15.8% of patients with MINS experienced an ischemic symptom. Conclusion: Among adults undergoing noncardiac surgery, MINS is common and associated with substantial mortality.

Tourism is one of the sectors believed to be able to contribute to the process of economic diversification in Brunei Darussalam. Kampong Ayer, which literally means ‘Water Village’ is one of the obligatory tourism attractions in the country, as there is an expression that says that a visit to Brunei Darussalam is not valid if one does not visit Kampong Ayer. Although there exists a tourism potential, there are challenges that must be addressed in order to promote tourism in Kampong Ayer, and to convince tourists of the uniqueness of this historic place. These include waste disposal problems, crime, loss of authenticity, as well as the lack of information, facilities and tourist services in Kampong Ayer. Aside from the prospect of generating income, tourism development in Kampong Ayer can also lead to the preservation and revival of the socio-cultural heritage of its community.

The increasing number of the Computer Numerical Control (CNC) machines usage in the manufacturing field appears to suggest that they are expected to be in good running condition. Machine tools such as CNC vertical milling machines are meant to produce precise work parts. Motion errors are factors which can directly affect the accuracy of the machine. This study presents an opportunity for interested parties to understand the characteristics of motion errors that exist in the CNC vertical milling machines with different feed rate settings. The purpose of this project is to find out any abnormalities apparent to the machine performance as the feed rate setting is increased. The motion errors of the CNC machines were examined by using a measuring device, namely Double Ball Bar (DBB). This equipment is designed to examine machine performance by measuring the accuracy of its movements. This device, which has two balls of identical size at the end of the bar, was mounted on a spindle and onto a special holder which is mounted on the working table. The machine is programmed to move in a circular motion, clockwise and anti-clockwise in three planes, XY, YZ and ZX. Any deviation from the standard data will represent the imperfection of the machines condition, especially mechanical components such as the slide bearing, spindle bearing or servo motor responses. By knowing the most significant error origin, the corrective countermeasures can then be carried out.

Three new compounds, 4-hydroxymethylene-7-(9,9,13-trimethylcyclohexyl)-heptanyl-3′,7′,7′-trimethylcyclohexa-2′,4′-dien-1′-oate (1), 1-(n-hexadec-7-enoxy)-6-(n-octadecanoxy)-β-D-glucopyranoside (2), and (Z)-12-hydroxy-9-octadecenoic acid-12-β-D-glucopyranoside (3), along with the known compound hexacosanoic acid (4), were isolated and identified from the rice hulls of Oryza sativa. Their structures were elucidated by 1D and 2D NMR spectroscopic techniques (1H-1H COSY, 1H-13C HETCOR, DEPT) aided by EIMS, FABMS, HRFABMS, and IR spectra.

One new compound 3,7,11,15,19-pentamethyl-9α,10α,11α,17α,18α-pentahydroxy-n-tetracosan-1-oxy-p-hydroxycaffeoate (oryzaterpenyl caffeoate) (1), together with three known fatty acids linoleic acid, stearic acid and myristic acid were isolated and identified from the rice grain of Oryza sativa. The structure of the new compound was elucidated by 1D and 2D NMR spectroscopic techniques (1H-1HCOSY, 1H-13C HETCOR) aided by EI-MS, and IR spectra.

The year 2004, marking the 20th anniversary of Brunei's independence, signalled unexpected change as the Legislative Council was reinstated after being suspended since 1984. The performance of the economy was lacklustre despite record oil prices. However, the country continued to enjoy peace and stability. The event of the year that most occupied public and media attention was the royal wedding of the Crown Prince.

A novel approach for designing a narrow dual Bandpass Filter (BPF) using microstrip Coupled-Line Resonator (CLR) is presented in this paper. The proposed CLR consists of butterfly radial stub and 45° mitred bending with new 'bell'-shaped structure. The proposed BPF consisting of two fundamental resonant modes with the resonant characteristic has been investigated using ADS software. To validate the design and analysis, the dual BPF was fabricated and measured. It is shown that the measured and simulated performances are in good agreement. A dual-band response BPF that operates at 2.4 GHz and 5.75 GHz is designed and implemented for wireless applications.

A 0.7 dB (min.) low noise figure PHEMT LNA at 5.8 GHz using an inductive drain feedback that is applicable to the WiMAX 802.16 standard. The amplifier uses FHX76LP superHEMT low noise FET. The Ansoft Designer was used during the design process. The low noise amplifier (LNA) produced the forward transfer gain (S21) of 43.74 dB. The return loss (S12), input reflection (S11) and output reflection (S22) are -52.41 dB, -10.60 dB, -18.22 dB respectively. The measured 3dB bandwidth of 1.24 GHz has been achieved. The input sensitivity is -80 dBm compliant the standards required by IEEE 802.16.

The main goal of this work is to investigate the performance of zirconia toughened alumina (ZTA) and ZTA reinforced with magnesium oxide (MgO) used as cutting insert in end milling of AISI 1018 steel with hardness of 27 HRC. Performances of the cutting insert were compared according to tool life and surface finish of workpiece. Insert flank wear that indicates tool life was studied carefully using Optical 3D Surface Metrology. Surface roughness values were evaluated using Surftest Sufrcom 130A. Both of the cutting inserts failed to exhibit good performance in end milling operation. However, wear condition and magnitude of the ZTA reinforced with MgO insert was slightly better than ZTA insert. Addition of MgO may increase wear resistance.

Toxic metals like lead, bismuth, mercury and zinc-aranyl have been found to repress the carbonaceous oxygen demand. The biological seed was developed from trade waste of Glaxo Laboratories. Three concentrations: 5, 10 and 15 mg 1 −1 of the metals were used to observe repression of carbonaceous oxygen demand of amino acid, methionine, used as substrate. Rate constants, ratios of ( t / y ) 1.3 and COD: BOD were computed.

Atomic absorption spectrophotometric studies were carried out to detect the presence of Cd and Zn in samples of fifteen commercial fertilisers, fifteen productive soils, eight barren soils, four garden soils and fifteen river water samples. The concentrations of Cd and Zn in fertilisers, productive soils, barren soils, garden soils and river water were recorded as 1·2–7·9 and 17–3070 mg kg −1 , 0·9–5·9 and 55–95 mg kg −1 0·04–0·06 and 7·5–10 mg kg −1 , 0·4–0·75 and 7·8–11 mg kg −1 and 0·5–2·3 and 8·5–18·5 mg litre −1 , respectively. In addition, soil samples were analysed for sand, silt, clay, pH, electrical conductivity, water soluble salts, osmotic pressure, cation exchange capacity, CaCO 3 and organic matter.

Assessment of completeness of vagotomy has always been an irksome and time-consuming affair. The commonly employed test of insulin-induced hypoglycaemia (Hollander) is tedious, risky and associated with practical limitations and theoretical objections, which have resulted in its being replaced by the modified sham feed technique in some centres. The postprandial alkaline tide is attributed to HCO3− release consequent to H+ secretion. Any procedure which reduces acid secretion is expected to affect the postprandial urinary pH. This study was performed to evaluate the effect of vagotomy on the postprandial alkaline tide by measuring prevagotomy and postvagotomy fasting and postprandial urinary pH. The results show that postprandial urinary pH falls after vagotomy and this method may be used to assess the completeness of vagotomy. The proposed test is convenient and may be used as a screening method in the assessment of vagotomy and other acid reducing operative procedures, if further validated, by comparison with already established tests.